Fuel Pump Running Backwards
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=43199
Printed Date: May-06-2024 at 4:21pm
Topic: Fuel Pump Running Backwards
Posted By: wolfman
Subject: Fuel Pump Running Backwards
Date Posted: July-20-2018 at 1:50pm
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Fuel pump failed, took it apart, seals and rubber in good condition but a check valve fell out of the hole. Put it back in, reverse of the other one that was still in place. Put back in boat but now it pumps backward. I think I put something in backwards but cant figure out what it would be. Any help apreciated. Thanks. ------------- 1978 Ski Tique 302 |
Replies:
Posted By: KENO
Date Posted: July-20-2018 at 2:06pm
Wild guess time here  Since there's not much info given, I'll guess it's a Carter pump maybe You say the check valve fell out , does this mean you took it apart and the valve was already out so you didn't know which way it should go back in? Does your pump have 3 check valves total or just 2? If it has 3 , which most of the marine Carter's do, the 2 that are side by side go in the same way not opposite from each other.. I'll bet that's what's backwards If it fell out on it's own, how are you making sure it stays in and doesn't fall out again. |
Posted By: wolfman
Date Posted: July-20-2018 at 2:24pm
It has two, heres a pic. Looking again it seems they are both backwards, strange since only one fell out.  KENO - this one has two, are they both supposed to be the same way? ------------- 1978 Ski Tique 302 |
Posted By: KENO
Date Posted: July-20-2018 at 2:32pm
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No, that's an AC dual diaphragm pump and that's how they should be arranged. Do the little flaps in the check valves seat ? And move back and forth(not stuck) ? If not you short cycle the discharge right back to the suction. That sounds like what's happening to you. |
Posted By: wolfman
Date Posted: July-20-2018 at 2:51pm
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I did check them and they both move freely. I will check the seating again but I think they were ok. The flow was not great from cranking the engine but I could feel suction on the wrong side and output on the wrong side. Here is a theory. The one that was still in was put in backwards at factory or PO, but still worked. Looking at this pic, they sure both look backwards to me. As far as keeping them in, they seem tight, is there something more I can do? ------------- 1978 Ski Tique 302 |
Posted By: KENO
Date Posted: July-20-2018 at 3:15pm
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I'd say that's a pretty good theory if your inlet and outlet lines from the pump were swapped with each other since I just took one apart enough to see the valves and they are backwards from yours. Getting the picture here is a bit of a challenge right now but I'll get a picture up with the same angle as yours, inlet on the top and outlet on the bottom.and you'll see that the valves are opposite of yours. The one I took a picture of works too Picture coming soon |
Posted By: KENO
Date Posted: July-20-2018 at 3:25pm
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Here's the picture Same orientation inlet on top, outlet on bottom and the valves are opposite in the pictures. And the valve flaps make sense in the picture I just put here, like you said yours seem backwards  Yours is clocked differently with the pump body but that shouldn't matter. |
Posted By: wolfman
Date Posted: July-20-2018 at 4:59pm
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That makes sense. I will flip them both. Maybe the one being backwards is what made the other fall out. Thanks KENO! ------------- 1978 Ski Tique 302 |